Reciprocating and rotating drum concentrator



July 22, 1947. v 2,424,367

RECIPROCATING AND ROTATING DRUM CONCENTRATOR Filed Mrch 5, 1945 2 Sheets-Sheet 1 ATTOPNEK July 22', 1947. J. M. NICOL RECIPROCATI NG AND ROTATING DRUM CONCENTRATOR Filed March 5, 19 45 '2 Sheets-Sheet 2 I IN V EN TOR,-

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Patented July 22, 1947 RECIPROCATIN G AND ROTATING DRUM CON CENTRATOR John M. Nicol, Mill Valley, Calif., assignor to Geo. G. Titzell, Jr., San Francisco, Calif.

Application March 5, 1945, Serial No. 581,028

4 Claims. 1 The present invention relates to ore classifiers, and constitutes an improvement upon the machine for which United States Letters Patent No. 2,053,802 were granted to me September 8, 1936.

The principal objects of the invention, in general, are the same as those stated in my said prior patent, viz: to provide a machine for continuously separating heavier particles from lighter particles in a stream of unclassified metal or mineral bearing material, such for example as gold or tin bearing gravels from placer deposits.

Specific objects of the present improvements are to provide more rapid and complete classification, and more positive and effective advance movement of the stream of material, than was possible in the machine of my said prior patent, these objects being achieved by a novel means for mounting the drum whereby it has a longitudinal jigging motion while rotating.

Other objects and advantages of the present invention will be apparent from the following specification, which should be read with the understanding that changes, withimthe scope of the claims hereto appended, may be made in the form, construction and arrangement of the several parts, without departing from the spirit of the invention.

Reference will be made to the accompanying drawings, wherein:

Fig. 1 is a side elevation, partly broken away, of my complete machine.

Fig. 2 is a transverse section on of Fig. 1.

The drum of my present concentrator is essentially similar to that described in my said prior patent, and comprises a cylindrical shell having interior circumferential cross rifiies l and longitudinal lifters t of less height than said cross riflies. A feed chute 9 conveys unclassified material into one end of the drum, and a discharge chute it receives the waste material from the other end. A launder H, supported by brackets I2, is positioned within the drum to receive the concentrate picked up b the lifters 3. Water is introduced into the drum through a pipe I3, and discharged therefrom against the launder II and the lifters 8. The drum is rotated, at slow speed, preferably not more than two revolutions per minute, by any suitable means such as a V belt I4 running in a grooved ring l5 secured to the outside of the drum. The drive mechanism (not shown) should provide for adjustment in the speed of the drum, to suit different types of material.

Each rifile 1 is provided with a gap [6, So that the line 2-2 boulders and irregular shaped rocks and other objects can pass through the. and the gaps of successive cross rifiies are staggered, to form a spiral escape path for such irregular objects to prevent packing of the rifiles. Up to this point, the present machin is similar to that of my said prior patent.

In my proved machine, the drum is provided with an inwardly inclined flange H at its inlet and an outwardly inclined or flared flange i 8 at its discharge end, so that the material will pass through it even when its axis is level. However, the mounting for the drum, to be described later, provides means for adjustably tilting its axis to suit the particular material being run.

The launder it comprises a shallow pan positioned at or slightly above the center of the drum, and having its bottom sloping down to a discharge opening H near its forward end, i. e., near the inlet end of the drum. A trough it! leads from said opening beneath the pan and out through the discharge end of the drum. The edge of the pan l l on the side at which the drum is rising is positioned as close as possible to the cross riilles I, and the opposite side of the pan has an upwardly inclined apron 25, also close to the cross riiiies. The pan therefore catches all or almost all of the concentrates from the lifters 8. I have found that a small number of lifters are effective, and have shown four in the drawing, equally spaced around the drum. The interior of the drum, between the cross riiiles l and lifters 8, may be provided if desired with a suitable wear resisting lining, not shown, such as rubber or other similar material.

My improved mounting for the rotating drum comprises a base frame 2!, one end of which is supported by a hinge 22 and the other end by screws 23, whereby it may be tilted to adjust the inclination of the drum axis. The frame 2| has uprights 2d at its sides, braced by inclined pieces 25, and said uprights support horizontal rails 28 upon which are mounted rollers 27. A cradle is suspended between the sides of the base frame, and comprises horizontal rails 28 which rest upon the rollers 21, vertical suspension members 29, horizontal bottom members 30, and bracing 'gussets 3!, all rigidly connected together by welding or riveting. Rollers 32 are mounted in journal brackets 33 inside the cradle, at its'bottom and sides, and the drum rests and revolves upon and between said rollers. Flanges 34 on the drum serve as guides to prevent its endwise movement on the supporting rollers 33.

A transverse shaft 35 is mounted in suitable bearings at one end of the base, and carries an eccentric 3B. A rod 31 connects the strap 38 of said eccentric with the adjacent nd of th cradle, so that as the eccentric revolves, the cradle and the drum are given a longitudinal reciprocating or jigging motion. The throw of the eccentric is preferably about one inch. The rod 3'! is connected to the cradle by an adjustable cushioned coupling comprising a trunnion block 39 pivotally mounted in a bracket 4% secured to the end of the cradle. The rod 3! slides freely through the trunnion block, and has a spring M at each end, compressed between said block and adjustable nuts 62. By adjusting said nuts, the range of movement of the cradle can be varied, as well as the cushioning effect of the springs.

The shaft 35 is rotated by any suitable means, such as a belt, not shown, passing over a pulley 43 on said shaft. The driving means should provide for variable speed, so that the optimum rate of vibration or jigging of the cradle and drum can be obtained.

In the operation of my concentrator, the unclassified material is fed into the drum from the chute 9 with sufficient water to produce the necessary boil and to wash the coarser and lighter waste material over the cross rifiles l and out into the discharge chute id. The fines, in which the values are concentrated, settle to the bottom between the cross riffies and are elevated by the lifters 8 and dumped into the launder ll. Suitable jets of water issuing from orifices in the spray pipe i3, assist in removing the fines from the lifters 8 and in washing them from the launder into the discharge trough IS,

The action of the rotating drum with its internal cross riflles and longitudinal lifters is somewhat similar to that of the ordinary stationary sluice box, except that the fines are continuously removed from the riiiles, and therefore there is no packing and clogging of the riflles, which would permit an increasing amount of fines to pass over and be lost. The longitudinal jigging motion of the drum, which is an essential novel feature of the present invention, keeps the mass of material agitated, assists and accelerates the settling of the heavy fines so that they are more surely caught by the riiiles and removed by the lifters, and accelerates the movement of the coarser waste through the drum.

The gaps HS in the cross riflles, arranged in a helical path from the intake to the discharge ends of the drum, provide an escape way for boulders and larger irregular pieces of rock that might otherwise, on account of their size and shape, fail to pass over the riffies and consequently clog the same and cause the fines to pack.

By having the jigging cradle mounted on elevated rails at about the height of the axis of the drum, which is above its center of gravity when loaded, and by providing the supporting rollers 32 high up on the sides of the drum as well as at its bottom, I minimize the tendency of the drum and the cradle to jump off their respective supporting rollers during their reciprocating movement.

I claim:

1. A drum concentrator comprising a movable dru having its axis approximately horizontal, means for rotating said drum about its axis, means for introducing unclassified material into one end of said drum, means for advancing said material through said drum and discharging the coarser portions thereof from the other end, spaced transverse rifiles secured to the inner surface of the drum, longitudinally disposed lifters of less height than said riffles extending between them, a launder within the drum positioned to receive the finer portions of said material from said lifters, said launder sloping downwardly toward the intake end of the drum and having a discharge aperture at its lowest point, a discharge pipe extending from said aperture beneath the launder and out through the discharge end of the drum, and means for reciprocating said drum longitudinally to assist the separation of the lines from the coarser material.

2. A drum concentrator comprising a movable drum having its axis approximately horizontal, means for rotating said drum about its axis, means for introducing unclassified material into one end of said drum, means for advancing said material through said drum and discharging the coarser portions thereof from the other end, spaced transverse riilles secured to the inner surface of the drum, longitudinally disposed lifters of less height than said rifiles extending between them, a launder within the drum positioned to receive the finer portions of said material from said lifters, a frame having spaced side members rising to the approximate level of the center of the drum, a movable cradle positioned between said frame side members, said cradle having a bottom and side members, the upper portions of said cradle side members being movably connected with said frame side member-s whereby said cradle is suspended between the sides of said frame, rollers mounted on the bottom and sides of said cradle for rotatably supporting said drum, and means for reciprocating said cradle longitudinally of the axis of the drum to assist the separation of the lines from the coarser material in said drum.

3. A drum concentrator comprising a movable drum having its axis approximately horizontal, means for rotating said drum about its axis, means for introducing unclassified material into one end of said drum, means for advancing said material through said drum and discharging the coarser portions thereof from the other end, spaced transverse riflles secured to the inner surface of the drum, longitudinally disposed lifters of less height than said riilles extending between them, a launder within the drum positioned to receive the finer portions of said material from said lifters, a cradle within which said drum is rotatably mounted, said cradle having a bottom beneath said drum and side members rising on each side thereof to the approximate level of the center of said drum, a frame upon which said cradle is movably supported, said frame having side members positioned outside the cradle side members, the upper portions of said cradle side members overlying the upper portions of said frame side members, rollers interposed between the side members of said cradle and said frame, whereby said cradle is suspended from the frame side members, and means for reciprocating said cradle longitudinally of the axis of the drum to assist the separation of the fines from the coarser material in said drum.

4. A drum concentrator comprising a movable drum having its axis approximately horizontal, said drum having a feed aperture bounded by an inwardly inclined flange at one end and a discharge aperture at the other end larger than said feed aperture, means for rotating said drum, means for introducing unclassified material into the feed end of said drum, means for advancing said material through said drum and discharging the coarser portions thereof from the other end, spaced transverse rifiies secured to the inner surface of the drum, longitudinally disposed litters of less height than said riflies extending between them, a launder within the drum positioned to receive the finer portions of said material from said lifters, a cradle within which said drum is rotatably mounted, said cradle having a bottom beneath said drum and side members rising on each side thereof to the approximate level of the center of said drum, a frame upon which said cradle is movably supported, said frame having side members positioned outside the cradle side members, the upper portions of said cradle side members overlying the upper portions of said frame side members, rollers interposed between the side members of said cradle and said frame, whereby said cradle is suspended from the frame side members, and means for reciprocating said 6 cradle longitudinally of the axis of the drum to assist the separation of the fines from the coarser material in said drum.

JOHN M. NICOL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,053,802 Nocol Sept. 8, 1936 287,840 Malry Nov. 6, 1883 299,337 Brotherhood May 27, 1884 FOREIGN PATENTS Number Country Date 472,997 France Sept. 1, 1914 1,151 Great Britain 1909 

